How to automatically navigate to the current class in Intellij Idea Project Tool Window?

Navigate (View in older versions)| Select In... (Alt+F1), Project View (Enter).

It's also possible to enable Autoscroll from Source option in the Project View so that current file is automatically selected.

IntelliJ IDEA 2019

Left click on the wheel > Always Select Opened File

Always Select Opened File

There is also: Open Files with Single Click - the selected file from the tree view will be opened in the right side.

Right click on Project/Packages area > Autoscroll from Source

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Left click on the wheel > Autoscroll from Source

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There is also: Autoscroll to Source - the selected file from the tree view will be opened in the right side.

Try Alt F1(Select Target dialogue) + Enter.